All of lore.kernel.org
 help / color / mirror / Atom feed
From: Al Viro <viro@ZenIV.linux.org.uk>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Matthew Wilcox <matthew@wil.cx>,
	LKML <linux-kernel@vger.kernel.org>,
	linux-fsdevel@vger.kernel.org,
	Stephen Smalley <sds@tycho.nsa.gov>,
	Christoph Hellwig <hch@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Eric Paris <eparis@parisplace.org>,
	"Theodore Ts'o" <tytso@mit.edu>,
	Dave Chinner <david@fromorbit.com>,
	James Morris <james.l.morris@oracle.com>,
	Paul Moore <paul@paul-moore.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
	stable <stable@vger.kernel.org>
Subject: Re: [PATCH] vfs: Fix possible NULL pointer dereference in inode_permission()
Date: Thu, 9 Jan 2014 22:31:27 +0000	[thread overview]
Message-ID: <20140109223127.GM10323@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20140109165012.391db81e@gandalf.local.home>

On Thu, Jan 09, 2014 at 04:50:12PM -0500, Steven Rostedt wrote:

> > We'd then have to get rid of all the call_rcu() invocations in individual
> > filesystems' destroy_inode methods, but that doesn't sound like a bad
> > thing to me.

Check what e.g. XFS is doing...

> Which is another reason that I didn't do it, as I didn't know all the
> happenings inside the ->destroy_inode() calls. But yeah, I agree with
> this.
> 
> Also, can iput() sleep? If not then we are OK. Otherwise, we need to be
> careful about any mutex being grabbed in those call backs, as the
> rcu_callback can't sleep either.

iput() definitely can sleep (that's when actual truncation and inode
freeing is done for opened-and-unlinked files - on the final iput() after
close()), but that' irrelevant here - fsnotify_delete_inode() grabs
a bunch of mutexes, which makes calling it from rcu callback no-go.

  reply	other threads:[~2014-01-09 22:31 UTC|newest]

Thread overview: 23+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-09 21:27 [PATCH] vfs: Fix possible NULL pointer dereference in inode_permission() Steven Rostedt
2014-01-09 21:42 ` Matthew Wilcox
2014-01-09 21:50   ` Steven Rostedt
2014-01-09 22:31     ` Al Viro [this message]
     [not found]       ` <CA+55aFzCTPYEQCPnLBi1CwmMTocVqCFiCuJ391HkVx1CMw61ug@mail.gmail.com>
2014-01-09 23:10         ` Paul E. McKenney
2014-01-09 23:25         ` Steven Rostedt
2014-01-09 23:27           ` Steven Rostedt
2014-01-09 23:37             ` Eric Paris
2014-01-09 23:45               ` Steven Rostedt
2014-01-09 23:53               ` Linus Torvalds
2014-01-10  0:06                 ` Al Viro
2014-01-10  0:09                   ` Al Viro
2014-01-10  0:18                   ` Linus Torvalds
2014-01-10  2:36                     ` James Morris
2014-01-10  9:31                   ` Christoph Hellwig
2014-01-10  9:31                     ` Christoph Hellwig
2014-01-10 18:14                     ` Ben Myers
2014-01-10 18:14                       ` Ben Myers
2014-01-11 10:32                       ` Christoph Hellwig
2014-01-11 10:32                         ` Christoph Hellwig
2014-01-09 23:45             ` Paul E. McKenney
2014-01-09 23:59               ` Steven Rostedt
2014-01-10  0:44                 ` Paul E. McKenney

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20140109223127.GM10323@ZenIV.linux.org.uk \
    --to=viro@zeniv.linux.org.uk \
    --cc=akpm@linux-foundation.org \
    --cc=david@fromorbit.com \
    --cc=eparis@parisplace.org \
    --cc=hch@infradead.org \
    --cc=james.l.morris@oracle.com \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=matthew@wil.cx \
    --cc=paul@paul-moore.com \
    --cc=paulmck@linux.vnet.ibm.com \
    --cc=rostedt@goodmis.org \
    --cc=sds@tycho.nsa.gov \
    --cc=stable@vger.kernel.org \
    --cc=torvalds@linux-foundation.org \
    --cc=tytso@mit.edu \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.